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Flexible (?) filler for after welding?

Posted: Sun May 03, 2015 10:28 pm
by mattinhertford
Hi all,

I've just finished welding in a new corner into the boot area, my first ever on-car welding (very chuffed :lol: ).

[frame]Image[/frame]

...and there are some gaps that could do with some sort of filler just to stop muck getting caught in them, and water coming in etc....any suggestions? Photo

I know in a perfect world my welding would have been seamless and so there would be no need for filler, but it was my first try, mainly to stop the previous hole being an MOT fail....so I'm happy for now and can always re-do in a few years when my welding is perfect :o

[frame]Image[/frame]

I mention flexible filler only because there is always a tiny bit of movement so thought a solid-solid one would just crack?? Haven't done any car body filling for 20+ years so totally unsure of what people use these days. In the second photo its the gap between the new floor piece and the new upright piece at the end...which are both welding together ina lip the other side.

Thanks

Re: Flexible (?) filler for after welding?

Posted: Mon May 04, 2015 6:34 am
by tysonn
Just buy a tin of seam sealer and apply into the joints with your finger or a brush.Once its gone off paint as normal.
Mick

Re: Flexible (?) filler for after welding?

Posted: Mon May 04, 2015 8:06 am
by mattinhertford
Ok, thanks Mick.

Re: Flexible (?) filler for after welding?

Posted: Mon May 04, 2015 8:28 am
by ManyMinors
Although make sure you first thoroughly prime the repairs with a good quality rust preventing bare metal primer BEFORE using the seam sealant which has no rust preventing properties at all :wink:

Re: Flexible (?) filler for after welding?

Posted: Mon May 04, 2015 9:10 am
by chickenjohn
Yes, prime the areas, including any pits with a good anti rust primer then apply brushable seam sealer to seal any welds and seams.

Good work on the repair by the way!

Although, the ultimate in avoiding getting any water into your welds is to butt weld. The over lap you have there is in a vulnerable area, if you can for your next repair, butt weld and grind down. Butt welds are much easier to get smooth and to prime and seal afterwards and there being no overlaps, there are not areas for water to get in and rust develop.

Re: Flexible (?) filler for after welding?

Posted: Tue May 05, 2015 1:37 pm
by mattinhertford
Thanks ChickenJohn, duly noted about the lap-weld/butt-weld preferences. I reckon I will be re-doing this area again in a few years, when I have perfected my welding techniques!

At the moment I can't get a decent continuous seam weld of any sort, hence the above being a series of spot/tack welds. I gave it a good few whacks with a rubber hammer and its a strong bind, just not pretty!

I need to read up some of the forums on mig-welding.co.uk to see where I'm going wrong. I keep getting blow through when I try and seem weld. I think I need to move along faster, and therefore increase wire speed too. I'll read up on it.

I'm chuffed though as it took me a whole two days to do this, lots of measuring, templating, cutting, banging, grinding, more cutting etc....so I reckon I've saved a couple of hundred quid from out-sourcing this, as whilst they'd be faster, it still would have taken a few hours at ££ per hour.

I keep telling my wife the money I've saved.....but she's not convinced!! :-?

Next welding job (for the MOT) is a new crossmember end....I have the new end, but I think it needs a bit more than spot/tack welding with tiny beads for that area :o :o

Re: Flexible (?) filler for after welding?

Posted: Tue May 05, 2015 1:42 pm
by tysonn
Is it a gasless mig?
Mick

Re: Flexible (?) filler for after welding?

Posted: Tue May 05, 2015 2:11 pm
by amgrave
When you do a seam weld don't try to do it in one run, it does not matter how low the welding current will go the heat build up will melt the metal and run off leaving a gap. Do the weld in short runs stopping and starting to allow the metal to cool a little to end up with a continuous weld. The secret is to watch the heat glow. Weld until the glow is nearly white then pause until the glow is dull red then weld again till nearly white and so on. There is a lot of other factors to getting a thin sheet weld right but practice is the only way. Best of luck to you.

Re: Flexible (?) filler for after welding?

Posted: Wed May 06, 2015 5:17 pm
by MrIan
Yes a series of tack welds about 1" / 2" apart to hold it all in line then seam weld between the tacks. Start one end then 2nd weld at other end alternating to help with heat build up. Practice practice practice !!!! :lol: